Nepenthes dubia is a highland species that is relatively new to cultivation. The Nepenthes Nursery has it in tissue culture while Borneo Exotics has small plants of seed origin. Borneo Exotics says that there is some orange in some of the small seedlings so there is some differences. Whether the orange hue will be maintained into adulthood has yet to be seen. Once the seed grown plants are gone BE usually has some clones in tissue culture. This species grows similar to N. inermis and looks almost exactly like it except for the peristome that N. inermis lacks.. It's a smaller scrambling vine type of Nepenthes. I grow mine outdoors in typical highland conditions. The small plants grow like typical highlanders too and that means not real quick but quicker than other highlanders.. I suspect that once they get fully acclimated and going, then they tend to grow more rapidly. Now that this species has been available for a few years, larger plants should start appearing in the forums to get an idea what the adult pitchers will look like. 

Cultivation: easy; moderate grower for a highlander, grows as a scrambling vine
Market availability: size 2, possible size 3; available
Species variability: possible variation from seed grown plants but not that much difference
$ / size: expensive; $70.00 to $90.00 
Cuttings: none available for trade
Sex: unknown